Electric heater.



G. v. K. GREENE.

ELECTRIC HEATER. APPLIQATION PILED'FBB-19, 190s.

Patented Jan. 19, 1909.

'UNITED sTATns PATENT ormcn.

GEORGE V. K. GREENE, OF NEW YORK, N, Y., ASSIGNOR TO E. ARDEN NOBLETI,

oir-Naw YORK, Y.

ELECTRIC HEATER.

Specication of Letters Patent.

Patented'an. 19. 1909.

To all whom it may concern:

Beit known that I, Gnoacn v. K. GREENE, a citizen of the United States, residing at the city of New York, county ot New York, and State of New York, have invented certain new and useful Improvements in Electric' Heaters, of which the tollo\.ving is a specification.

My invention relatesto electric heaters and particularly to those wherein an electric current trayerses, during its course, a material of high resistance forming a heating element, it thereby rendering said material mentis entirely pnotected from contact with the operator, and to provide a heater wherein all danger of short-circuiting is absolutely avoided.

To these ends my invention consists `in the construction and arrangement ot' parts as shown in the drawings and specifically set forth in the appended claims.

In the drawings, Figure l is a plan or inside face view ot' one section of my heater, forming the base plate. the other section or covering plate being removed. l Fig. 2 is a plan view of the insideface of the covering section'. F ig. 3 is ameiilarged fragmentary plan of a corner 'of the base plate. Fig. 4 is an enlarged fragmentary iew of one cor'ner i ot the inside face. of the covering section.

Fig. .3 is a cross section thereof on the lines .fc5- Fig. Fig. 6 is a cross section on line z--e (Fig. 5).

Like characters in all the several views designate like parts.

2 designates a base plate molded or otherwise formed of insulating material such as unglazcd porcelain, American lava etc.

. I do not limit myself to any specific mateof'resistance' to heat.

rial, the only requirement being that it shall insulate the heating element and its terminals and that it shall have a high degree Thisl plate is of any desired thickness and is provided on its inner face with a4 continuous channel (3). This channel may be formed therein when the plate is molded. The channel is adapted to contain the heating clement and may be ot any required depth and width. .I have found that a channel three-eighths of an inch deep and one-quarter of an inch wide gives very excellent results. l merely give these figures for the sake of clearly demonstrating thecomparatively large size ot the heating element.

In order to obtain the greatest length of the heatingelemcnt and therefore the greatest heat-ing area, the channel preferably extends in a number ot turns backward and forward across the base plate 2, in the man ner shown in Fig'. i. The ends of the channel might extend directly to that edge of the pla-tc adjacent to the nearest coil or bend of the channel, but I would deem it preferable. to carry the channel around so that the ends will extend outward to the edge of the plate on the same side, as shown in Fig. 1.

The channel 3 is filled with material designated by the numeral 4: which will offer resistance to the passage of an electric current and which `will thereby become heated to the degree required on the passage of a current. The material filling this channel I term the heatingelement. I may use any material desired as the resistantheating element and in any form; preferably, I use a, resistant in the form ot' powder which is filled comparatively loosely into the channel or is compressed therein.

The heating element or resistant 4 does not extend to the margin of the base plate, that is to the outside of the casing formed by the base plate and covering, but stops short of the margin at the points marked g/*y in Fig. l. Terminals 5, 5 preferably are of brass and are inserted into the ends of the channel and are in contact with the heating element; the exterior ends of the .terminals being adapted to' be connected in circuit with any source of electricity.

The base plate and its heatingelement are covered by a covering plate 6 which tits upon the base' plate and is fastened tightly thereon by screws` or bolts 'which pass through the opening T on the margins ot' both plates. This covering plate is prefer;` ably ot' unglazed porcelain or other material of high resistance as above referred to. This plate might be made of stamped sheetmetal and the heating element insulated therefrom by sheets of mica or other means.

Theinner face of the covering plate '6 'ts tightly against the face of the base'plate 2 and in order to prevent the entrance ofair between the faces ,ofthelplates, cement is placed aroundthe margins of theplates'b'etween their adjacent faces,'thu`s completely filling the spaces and rendering the joint air tight. To make the joint still further ai-r tight l have provided one of the plates with a marginal rib 7 and the other has a marginal groove into which this rib will fit. ln the drawiings, l have shown the upper plate with the marginal rib 7 and the lower plate with the marginal groove 8. The rib' and groove are preferably made with inclined sides. Cement maybe placed in this groove, but preferably l place cement between the rib and the edge of the plates. rlhus, when the two plates are in place one upon 'the othe'r cemented Aas just-described,`

the rib on one plate engaging with the groove in the other, the heating element will be entirely isolated from contact with the air and oxidation of the element and its consequenudeterioration will be absolutely prevented.

- The exterior of the base plate 2 may be made with a groove around its edge or any desired portion thereof so that the heater may be supported on a suitable frame. lin Fig. 5 :i have shown an angle iron support engaging with this groove. As my heater is adapted to be used in a large variety of circumstances and undermany di'erent con* ditions l have not deemed it,necessary to show any particular variety o supporting frame as that is not within the scope of this invention. a

lWhile l have shown the channel 8 as being made entirely in the base plate 2 wish it understood that said channel' might be formed partly in the top plate and partly in the base plate. I do not wish to be limited to any of the details of construction shown nor to any specic material. The heating element may be formed of any desired resistant material, such as powdered carbon and the channel may traverse/the plates in any desired figure. The channel, however,

' should be continuous for each heating surface.

the heating element may be of great extent and a very large cross-section, though .formed of material far weaker and less rigid than would be possible were the heating element unsupported and uninclosed. rll`he heating element does not deteriorate for the reason Lanyposition desired and to a large variety lutely prevented and under no circumstances pQrtaniLpoint, adapted not only to revent extraneous damage to the heater but a so preventiii oxidation. vPlatesl of this character are' a apted to be easily handled, used in of circumstances where it would be impossible to use unprotected heaters. The device is simple,of a high heating capacity and may be much' more leasily used than heaters of ordinary construction.

A. further advantage resulting from the use of my invention is that there is no danger of short circuiting. The faces of. the two plates within which the heating element is linolosed absolutelywcontact one with the other so that the electricity cannot possibly pass. Neither canta short circuit be formed by the heating element being brought adjacent to metal or other'conducting material. This is one of thi`- most prominent .faults of electric heaters as ordinarily constructed and to it is due a large number of accidents. By inclosing the heating element within these non-conductiiig plates, all chance of short circuiting is absocan lire occur.l Of course, it is understood that the covering plate? and indeed for that matter, the base plate to a somewhat lesser extent on account of its thickness, becomes heated by this contact with the incandescent or heating element 3.

Having described my invention what l claim is:

1. An electric heater comprising two oonjoined plates of non-conducting material, one of said plates` bein formed with a continu,- ous channel, theen s of said channel opening to an edge of said plate, said channel being filled with a heating element of current resisting material, and means for engaging said heating element with a source of electricity, one of said lates being formed with a rib adjacent to its margin, the other of said plates being formed with a groove into which the rib is adapted to project and ma- 11o terial filling the space between the plates exterior to said rib. l

2. An electric heater comprising a iat, hollow case formed in two parts adapted to be fastened together the peripheral margins of 115 said plates having contact with each other, a heating element composed of electric current resisting material contained in the space bein airwtigh Contact with the bese niet@ v-na'rneva-to'this speoieation in the presenoe of around its entire edge, e heating eiement two subscribing witnesses, 4his 11th dey of 10 c oinposeciof an electric currentmeslsting ina- Febrliary 1908. terlal filling the channel o'the bese plebe, GEORGE V. K GREENEl and terminals contacting at their ends with the heating element and projecting to thev `Witnessesz edge of the base plate. FREDERIC B. WRIGHT,

In testimony whereof, have Signed my JOSEPHINE A. VERNON. 

